New York Daily News: By Kate Feldman – Thousands of flights were canceled Monday, prolonging an ugly weekend for holiday travel.

Of more than 2,500 planes grounded globally by noon Monday, almost 1,000 were within, into or out of the United States, according to Flight Aware. Since Friday, more than 4,000 flights within the US have been cancelled.

Monday’s mayhem was blamed on bad weather, particularly in the western US where winter storms shut down roadways and airways.

The National Weather Service warned Monday of “significant snowfall” along the West Coast mountain ranges and a pair of storm systems that will bring snow and “an icy wintry mix” to the Upper Midwest, Great Lakes, and Northeast.

“Travel delays due to icy conditions are possible in these regions, both on the ground and in the air,” forecasters said.

Travelers wait in a check-in line at Miami International Airport, Monday, Dec. 27, in Miami.
Travelers wait in a check-in line at Miami International Airport, Monday, Dec. 27, in Miami – Rebecca Blackwell/AP

And in a common 2021 refrain, COVID-19 has wreaked havoc on the airlines as well, with hundreds of flights being canceled over Christmas weekend due to crew members calling out sick amid a surge in the omicron variant of the virus.

An electronic sign advises travelers of the requirement to wear a face covering.
An electronic sign advises travelers of the requirement to wear a face covering – David Zalubowski/AP

Airlines, many of which have mandated vaccines for staff and crew, have been pressing the Centers for Disease Control and Prevention to lower the quarantine window for vaccinated workers from 10 days to five, similar to healthcare employees. Labor unions have pushed back.

“We recognize that how long a person should isolate is not a ‘one-size-fits-all’ number of days. We also note that fully vaccinated people may be less infectious for less time than unvaccinated people. Still, we consider your current 10-day recommendation to represent a prudent middle ground,” Sara Nelson, the president of the Association of Flight Attendants, said in a statement last week.